Titanium dioxide is prevalently used in a variety of industries. It is considered a metal and also naturally found on Earth. With its prevalent use, it is normal to question its safety, especially for those who are new to this mineral and want to start using it in their industry.

This article will highlight everything you need to know about this metal from the definitions, facts and its benefits in cosmetics and other industries. 

Definition of Titanium Dioxide

Titanium Dioxide

Titanium is one of the elements found in the Earth’s crust. It is also a common metal found in living things on Earth. This metal interacts with oxygen and forms a compound known as titanium oxides. Meanwhile, titanium dioxide is an oxide of titanium with a chemical formula of TiO2 which occur naturally.

This mineral is used as one of the ingredients in sunscreen due to its ability as a UV filter. Titanium dioxide has the ability to block the UV light absorption to the skin that can cause problems such as sunburn. Titanium white or Pigment White 6 (PW6), or CI 77891 is the name of this metal in the form of pigment.

Properties

This metal has a white solid appearance and is odorless. It also has extremely high melting and boiling points, which are 1,843 degrees Celsius and 2,972 degrees Celsius, respectively. That is why it naturally occurs in solid form. Even in its particle form, this metal is insoluble in water.

TiO2 has the ability to absorb UV light, therefore it appears as pure white. It has a higher refractive index than diamond and therefore has an excellent ability to scatter light. That is why TiO2 is an incredibly bright substance and usually used for aesthetic design.

Benefits and Uses

People have been using titanium dioxide for centuries. It is mostly used in a variety of industries which include paints, adhesives, paper, coatings, plastic, rubber, cosmetics, toothpaste, food colorants, sunscreen, and a lot more. 

There are two forms of production used in these industries, they are a pigment grade and an ultrafine product. 

1. Pigment grade

Ninety-eight percent of total TiO2 production is pigment grade. This type of grade is used for increasing brightness and white opacity to certain products. However, it doesn’t mean that this pigment is only used on brighter colors, darker shades also use TiO2 as one of their ingredients. Here are how the pigment-grade TiO2 is used:

a. Paints

In paints manufacturing, TiO2 is excellent to make the color more opaque and durable. Therefore, the paint will not come off or fade easily while at the same time protecting the surface.

Related: All You Need to Know about Kaolin Clay as Paints & Coatings

b. Rubber and Plastics

TiO2 is also used in rubber, adhesives, and plastics manufacturing to reduce the brittle. Additionally, plastics will neither be prone to cracking nor fading when exposed to light thanks to the TiO2.

c. Paper

Thanks to its white and opaque color, TiO2 is also used in paper manufacturing as coating.

Related: Kaolin in Paper Industry, the Current Production Trend

d. Cosmetics

In addition to sunscreen, TiO2 is used to hide blemishes and brightens the skin. Sometimes it is also added to other makeup products as a thinner to achieve certain effects.

e. Food Contact Materials and Ingredients

In food, beverages, supplements, and pharmaceutical products, TiO2 protects them from early degradation and thus enhances their longevity. Meanwhile, the purer form of pigment grade TiO2 is used in tablets and capsules as well as decorative purposes for some foods. 

2. Nanoscale TiO2

The ultrafine or nanomaterial product is used for products that need transparency and maximum UV light absorption.

a. Sunscreen 

TiO2 in the Nanoscale form is transparent while at the same time absorbing the UV light. Its particle is so small that it doesn’t reflect the light and absorbs the UV light instead. This creates a protective barrier for the skin from the danger of the sun’s rays. When used consistently, it helps prevent skin cancer.

b. Catalyst 

The nanoscale form is also used in catalyst applications. It is mostly used in the motor industry as well as power stations to remove harmful emissions and nitrous oxides, respectively.

Safety

In a low and controlled concentration, TiO2 is safe to use. The FDA in the United States assessed the safety of this metal for its various purposes. This organisation also issued guidance which mentions that TiO2 is safe in certain amounts as food colorant and cosmetics, including those applied around the eye. 

However, prolonged exposure at high concentrations may cause safety concerns, although not significant. Here are some of them:

1. Inhalation

When inhaled in high concentrations, this metal can cause nose and throat irritation.

2. Skin Contact

Skin contact can also lead to mild irritation for some people.

3. Eye Contact

When it gets into the eye, TiO2 can cause slight eye irritation as a ‘foreign object’. It may cause tearing, blinking, and discomfort in the eye. Temporary pain may also occur when the particles are rinsed away by tears.

4. Ingestion

Ingestion of this substance is not harmful.

5. Long-Term Chronic Exposure

Conclusions regarding long-term chronic exposure are still unclear due to the limited studies available.

6. Carcinogenicity

International Agency for Research on Cancer (IARC): Group 2B stated that this material may be carcinogenic or causing cancer based on animal information. It is usually associated with lung cancer. However, the American Conference for Governmental Industrial Hygienists (ACGIH): A4 stated that it is not classifiable as a human carcinogen and is still under review.

7. Teratogenicity/Embryotoxicity and Reproductive Toxicity

This material is not known to be teratogenicity or embryotoxicity, which are its ability to harm an unborn child. It is also not known to be dangerous for reproductive organs or reproductive toxicity. 

8. Mutagenicity

TiO2 is also not known to be a mutagen, so it should be safe when used in medical aid.

Titanium dioxide is a metal that is mostly safe to be used in a wider variety of industries. Although it is safe, people who work with this material should always use the appropriate personal protective equipment such as masks, gloves, etc. 

Additionally, the Department of Labor’s Occupational Safety and Health Administration has established a Permissible Exposure Limit for TiO2 total dust. Therefore, employers in the industries that process this material should always make sure that the workplace exposure is below the PEL set up on the guideline.